The present invention relates in general to the construction of signs which utilize flexible membranes to carry the display surface of the sign, and in particular to a new and useful facia which utilizes an expandable frame and other improved features to economically and effectively support and tension a flexible membrane to be used as a sign.
The use of flexible yet durable membranes in the construction of signs has been steadily increasing as the mechanisms for supporting and tensioning the flexible membranes have improved.
The tensioning of the sign membrane must be firm and secure since the sign must be exposed to weather and wind over long periods of time. It is also important that the membrane can be mounted in a quick and easy fashion not only for initial installation but also if and when the membrane is to be changed. A variety of mechanisms are known for grasping and holding the edges of the membranes and for tensioning these edges so that the membrane can be stretched on a frame.
Other considerations include the provision of sufficient space behind the sign for illumination, where the sign is to be illuminated, and the use of a mechanism for allowing the sign to extend around the corner of a structure in a continuous fashion where needed.
U.S. Pat. No. 2,899,764 to Oberlin, Jr. discloses a sign structure which is mounted on a vertical post by brackets which are spaced above and below the sign surface and are fixed around the post. The sign surface is tensioned vertically by turnbuckles which are connected between an edge of the sign and the bracket that is fixed, in turn, to the post. This reference does not include brackets that are slidably mounted along a section member, nor channels connected to ends of the brackets which are spaced away from the section member.
U.S. Pat. No. 3,537,201 to Huey et al. also uses vertically extending posts to support the upper and lower edges of a flexible sign membrane, but no tensioning mechanism is provided for moving the supports on the vertical posts to tension the membrane.
Another mechanism for tensioning a banner shaped sign is disclosed by U.S. Pat. No. 3,824,724 to Miller et al. which fixes one end of the banner to a vertical post and an opposite end of the banner to a spring loaded plunger. A sleeve for receiving the spring loaded plunger is also fixed to the post and vertical tensioning is provided by the spring loaded plunger. No bracket is disclosed which is slidably mounted to a section member and which is fixed to an edge of the banner so that sliding movement of the bracket through a tensioning element causes tensioning of the banner.
Transverse (horizontal) tensioning is disclosed by U.S. Pat. No. 4,459,773 to Sandlin et al.
Pivotally mounted brackets are used to tension upper and lower edges of a sign membrane in U.S. Pat. No. 4,833,805 to Roberson.
U.S. Pat. No. 4,864,756 to Rasmussen discloses a flexible enclosure which has upper and lower edges to which the upper and lower edge areas of a membrane are fixed. Vertical supports having one displacable end are used in connection with a bolt for spreading the inside of the enclosure to thus tension the membrane. Hollow members containing a rod around which the membrane is wrapped is utilized by Rasmussen to tension inner and outer corner areas of the sign membrane, horizontally.
U.S. Pat. No. 4,441,469 to Dahl discloses a channel structure (FIG. 11 of the reference) which contains a strip around which an edge area of membrane is wrapped, a lower edge of the strip being forced into a recess of a channel to fix the web as the web is tensioned around an opposite edge of the strip. Dahl does not utilized teeth in the channel recess for fixing one end of the strip however.
U.S. Pat. No. 4,539,724 to Messerschmitt and U.S. Pat. No. 4,554,754 to Stilling disclose two other approaches for fixing the edge area of a flexible membrane in a channel.